Air seeder distribution apparatus with purging air

ABSTRACT

An air seeder distribution apparatus has a manifold and a plurality of delivery conduit connected to ports of the manifold. A supply conduit carries a product air stream and is connected the manifold interior. A port valve when open connects a delivery conduit to the manifold interior through the port and disconnects same when closed. A purging conduit connects the supply conduit, at a clean air location configured to receive from the supply conduit a clean air stream with no agricultural products entrained therein, to the delivery conduit such that the clean air stream has an open path from the supply conduit to the delivery conduit. When the port valve is open the clean air stream flows through the purging conduit at a low first flow rate, and when the port valve is closed the clean air stream flows through the purging conduit at a second significantly greater flow rate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and benefit of CA Serial No.2,947,428, filed Nov. 4, 2016, the contents of which are incorporated byreference in its entirety and for all purposes.

FIELD OF THE INVENTION

This disclosure relates to the field of agricultural air seeders and inparticular an air distribution apparatus with valves on the ports tocontrol product distribution.

BACKGROUND

Agricultural air seeders include generally an implement frame and aplurality of furrow openers spaced across a width of the frame, andmovable to a lowered operating position where the furrow openers engagethe ground to create furrows as the frame moves along a field.Agricultural products such as seed, fertilizer, and the like are carriedin tanks mounted on the frame or a cart pulled with the frame anddistributed to the furrow openers by a product distribution system whereone or more fans create one or more air streams and metering devicesdispense the agricultural products into the air streams and the productsare carried through an air distribution network made up of conduits andmanifolds to the furrow openers, and then into the furrows. Furrowopener assemblies often create two (or more) separate furrows, such asone furrow for seed and a separate furrow for fertilizer, and separateair streams carrying different agricultural products are connected so asto deposit the different products in the separate furrows. In other airseeders, separate furrow opener assemblies may be used to create theseparate furrows.

There are different types of product distribution systems used onpresent day air seeders. In a Class A product distribution system, allagricultural products destined for a given set of furrows spaced acrossthe width of the implement are metered into a single air stream in aprimary supply conduit connected to a primary manifold. Such manifoldsare generally a thin cylinder with an inlet in a top or bottom of thecylinder connected to the supply conduit to receive the air streamcarrying agricultural products, and a number of outlet ports equallyspaced around a circumferential wall. Flat fan manifolds are also knownwhere the supply conduit directs the product air stream into one end ofthe flat manifold body which divides the product air stream intochannels with ports at the ends of the channels on the opposite end ofthe manifold body. Delivery conduits are connected to each port to carrythe air stream further downstream to another manifold or to a furrowopener as the case may be.

In such a Class A product distribution system the primary manifoldprovides primary division of the air stream and the agriculturalproducts carried therein by dividing and directing the air stream into anumber of different delivery conduits, each of which is in turnconnected to a secondary manifold. The secondary manifold providessecondary division of the air stream and the agricultural productscarried therein by dividing and directing the air stream into a numberof different secondary conduits, each of which is connected to a furrowopener to direct the air stream, and the agricultural products carriedtherein, into a selected furrow.

In a Class B product distribution system the metering device itself isdivided into a number of sections such that primary division of theagricultural products takes place prior to the products entering the airstream. Each conduit from a meter section is connected to a manifoldwhich provides secondary division of the air stream and the agriculturalproducts into a number of different secondary conduits, each of which isconnected to a furrow opener as in the Class A system.

Present day air seeders are often 80 or more feet wide, and a problemarises when a strip of a field to be seeded is much narrower than theseeder, as a considerable width of the field will be overlapped andseeded twice. It is most undesirable to leave even a narrow strip of afield unseeded as, without crop competition, weeds will flourish in thestrip providing seed for future years weed growth. Seeding the adjacentfield area twice, however, wastes valuable seed and fertilizer, and thecrop on the twice seeded field area generally has reduced yield and/orquality.

Thus it is desirable to provide a means to stop the delivery ofagricultural products to furrow openers in the overlap area by providingindividual control of the delivery of agricultural products to a numberof different sections of furrow openers across the width of the airseeder. U.S. Pat. No. 7,690,440 to Dean et al. discloses a Class Bproduct distribution system where the metering device is divided into anumber of sections, and where gates are provided at each meter sectionthat may be opened or closed to start or stop product flow from eachmeter section. The air seeder is configured so that each meter sectionsupplies agricultural products to a downstream manifold and from thereto furrow openers that are laterally arranged in order across a sectionof the width of the seeder so that stopping product flow to any manifoldstops product flow to a section of the air seeder. Thus as the strip offield to be seeded narrows to less than the width of the air seeder,product delivery is stopped to sections of the air seeder passing overpreviously seeded ground.

U.S. Pat. No. 7,555,990 to Beaujot takes a different approach byproviding valves on the outlet ports of the manifold. The describedsystem has a single manifold downstream from the metering device, andvalves are provided on each port of the manifold. Each port can thus beopened or closed, such that the delivery of the air stream with theentrained agricultural products to each furrow opener can be stopped orstarted, however a problem arises when a port is closed and the flow ofair through the downstream delivery conduit connected to the furrowopener is shut off. These delivery conduits very often do not slope downall the way from the manifold to the furrow opener, but have low areaswhere the conduit dips down and then rises. When the manifold ports areblocked, the air is instantly cut off and agricultural products in thedownstream conduit are no longer carried along by the air stream butsimply fall down, and can thus gather into one of these low areas andblock the conduit such that when the port gate is opened again the airstream will not flow through the blocked conduit and the furrow openerwill receive no product.

This problem of blocked conduits downstream from a blocked port isaddressed by U.S. Pat. No. 8,635,963 to Friggstad by having a two-wayvalve at each port which can block product flow through the port andsimultaneously expose the blocked port to a purging air flow that blowsproduct in the downstream conduit out into the furrow. A plenum ofpressurized air is fluidly coupled to the two-way valve to provide thepurging air flow to any exit port of the manifold that has been shut offfrom product flow.

When some of the manifold ports are closed in the systems of Beaujot andFriggstad, the flow of air through the downstream delivery conduitsconnected to the furrow openers is shut off and the air stream enteringthe manifold then must flow out through the open ports such that anincreased amount of air flows out each of the open ports. As the numberof closed ports increases, more and more air tries to flow through theopen ports and back pressure in the manifold increases. With the fansmost commonly used in air seeders to generate the air streams used fordistributing agricultural products through conduits, as the backpressure in the conduits increases, the volume of air moved decreases,and the velocity of the moving air decreases.

Thus, in the system of Beaujot, as back pressure in the manifoldincreases, the volume of the air stream entering the manifold isreduced, and the velocity of the air flowing through the supply conduitfeeding the manifold is reduced. The air stream must move through thesupply conduit at a minimum velocity that is sufficient to keep theagricultural products entrained in the air stream suspended therein.This critical velocity will be higher in a vertical section of thesupply conduit than in a horizontal section, as the air stream must movethe agricultural products upward against the force of gravity as opposedto moving the product laterally.

If the velocity drops below this “critical” velocity, the particles ofagricultural product will drop out of the air stream. Thus, in theBeaujot and Friggstad systems, as ports are closed the velocity of theair stream will at some point fall below the critical velocity, theagricultural products will start to drop out of the air stream, and layin the bottom of the supply conduit.

U.S. Pat. No. 8,690,488 to Jagow et al. addresses this problem. In Jagowwhen the port valve is closed to block product flow, an exhaust valve onthe supply conduit is opened to exhaust a flow of air similar to thatblocked when the port valve is closed. The Jagow system thereby keepssubstantially the same amount of air flowing through the supply conduitwhich addresses the air flow problems present with the Beaujot andFriggstad systems. In one version the exhaust air is directed through atwo-way valve which either opens the port to allow product flow into thedownstream conduit while blocking the exhaust air flow, or blocks theport to stop product flow while opening the exhaust and directing theexhaust air into the downstream conduit to purge the downstream conduitof product, similar to the system of Friggstad.

SUMMARY OF THE INVENTION

The present disclosure provides an air distribution apparatus for an airseeder that overcomes problems in the prior art.

The present disclosure provides an air distribution apparatus for an airseeder. The apparatus comprises a manifold body, and a plurality ofports defined through a wall of the manifold body, and a deliveryconduit is connected at an input end thereof to each port. A supplyconduit is connected at an output end thereof to an interior of themanifold body, and connected at an input end thereof to receive aproduct air stream with agricultural products entrained therein. On atleast a first port, a port valve is configured such that when the portvalve is open, a corresponding first delivery conduit is connected to aninterior of the manifold body through the first port and a first portionof the product air stream flows through the first delivery conduit, andsuch that when the port valve is closed, the first delivery conduit isdisconnected from the interior of the manifold body. A purging conduitis connected at an input end thereof to the supply conduit at a cleanair location configured to receive from the supply conduit a clean airstream with substantially no agricultural products entrained therein,and connected at an output end thereof to the first delivery conduit inproximity to the first port such that the clean air stream has an openpath from the supply conduit to the first delivery conduit. When theport valve is open the clean air stream flows through the purgingconduit at a first flow rate, and when the port valve is closed theclean air stream flows through the purging conduit at a second flow ratethat is greater than the first flow rate.

The present invention maintains air speed of the product air streamabove a critical velocity in the distribution network as ports areclosed and opened, and provides a purging clean air stream to clearagricultural products from delivery conduits and manifolds downstream ofa closed port valve. The present apparatus is simple and less costly tomake compared to the prior art system where a two way valve withappropriate controls is required to simultaneously open the purging airconduit while closing the port valve.

DESCRIPTION OF THE DRAWINGS

While the invention is claimed in the concluding portions hereof,preferred embodiments are provided in the accompanying detaileddescription which may be best understood in conjunction with theaccompanying diagrams where like parts in each of the several diagramsare labeled with like numbers, and where:

FIG. 1 is a schematic cut-away side view of an embodiment of the airdistribution apparatus of the present disclosure with the first portvalve open;

FIG. 2 is a schematic cut-away side view of the embodiment of FIG. 1with the first port valve closed;

FIG. 3 is a schematic top view of the manifold body of the embodiment ofFIG. 1;

FIG. 4 is a schematic side view showing the first delivery conduitconnected directly to a furrow opener.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

FIGS. 1 and 2 schematically illustrate an embodiment of an airdistribution apparatus 1 of the present disclosure. The apparatus 1 isshown as part of an air seeder product distribution network. Theapparatus 1 comprises a manifold body 3 comprising substantiallycircular top and bottom plates 5, as illustrated in FIG. 3, orientedsubstantially horizontally, and a substantially vertical body wall 7extending between the top and bottom plates 5A, 5B. Ports 9 are definedthrough the body wall 7, and a delivery conduit 11 is connected at aninput end thereof to each port 9.

A substantially vertically oriented supply conduit 13 is connected at anoutput end 13A thereof to the interior of the manifold body 3 through anaperture 15 in the top plate 5A. The supply conduit 13 extendssubstantially vertically up from the manifold body 3 to a curved elbow17 and then extends substantially horizontally from the elbow 17 to aninput end 13B thereof that is connected to receive a product air streamPAS with agricultural products 19 entrained therein. The product airstream PAS is provided by a conventional air seeder fan and meteringsystem.

A port valve 21 is configured such that when the port valve 21 is open,as shown in FIG. 1, the corresponding first conduit 11′ is connected tothe interior of the manifold body 3 through a first port 9′ and a firstportion PAS' of the product air stream PAS flows through the firstdelivery conduit 11′ to a downstream secondary manifold 23 which dividesthe first portion PAS' of the product air stream PAS into separate airstreams to each of a plurality of furrow openers 25 as is known in theart. The first portion PAS' of the product air stream PAS will be aproportion of the total product air stream PAS substantiallycorresponding to the number of ports 9.

When the port valve 21 is closed, as shown in FIG. 2, the first deliveryconduit 11′ is disconnected from the interior of the manifold body 3 andno part of the product air stream enters the first delivery conduit 11′.The air seeder system will typically be configured to correspondinglyreduce the amount of entrained agricultural products in the product airstream PAS to maintain a constant application rate of agriculturalproducts across the width of the air seeder.

A purging conduit 27 is connected at an input end 27A thereof to thesupply conduit 13 at a clean air location 29 configured to receive fromthe supply conduit 13 a clean air stream CAS with substantially noagricultural products entrained therein. In the illustrated apparatusthe clean air location 29 is at an inner radius of the elbow 17. Thevelocity of the product air stream PAS causes the agricultural productsto follow the outer radius of the elbow 17 when turning from thehorizontal to the vertical direction, such that little if any product ispresent at the inner radius, and a clean air supply can be obtained.

The purging conduit 27 is connected at an output end 27B thereof to thefirst delivery conduit 11′ somewhere in general proximity to the firstport 9′ such that the clean air stream CAS has an open path from thesupply conduit 13 to the first delivery conduit 11′.

When the port valve 21 is open as in FIG. 1, the air pressure of thefirst portion PAS' of the product air stream PAS is present at theoutput end 27B of the purging conduit 27, which pressure is onlyslightly less than the air pressure of the product air stream PAS at theclean air location 29. The pressure difference is due to pressure lossesas the product air stream PAS passes through the manifold body 3 andport 9′, but in any event the pressure differential is small and theclean air stream CAS flows through the purging conduit 27, and thenthrough the first delivery conduit 11′ with the first portion PAS' ofthe product air stream PAS, at a first flow rate that is virtuallynegligible for the purposes of the apparatus 1 and does not adverselyaffect air flows in the apparatus 1.

When the port valve 21 is closed, the air pressure of the first portionPAS' of the product air stream PAS is removed from the output end 27B ofthe purging conduit 27 and the air pressure of the product air streamPAS at the clean air location 29 causes the clean air stream CAS to flowthrough the purging conduit 27 and the first delivery conduit 11′ at asecond flow rate that is much greater than the first flow rate, andcomparable to the rate of air flow in the first portion PAS' of theproduct flow rate PAS since the air pressure at the output end 27B ofthe purging conduit is then about the same as at the clean air location29, which as described above is very close to the air pressure of thefirst portion PAS' of the product air stream PAS when the port valve 21is open.

Thus the air flow through the supply conduit 13 remains substantiallythe same whether the port valve 21 is open or closed, and problems ofreduced air flow in the supply conduit 13 are avoided.

FIG. 4 schematically illustrates an alternate arrangement where thefirst delivery conduit 11′ is connected at an output end thereofdirectly to a furrow opener 25 which may in some cases be preferred inorder to stop and start the flow of agricultural products to each furrowopener 25 independently.

The present invention thus maintains air speed of the product air streamPAS above a critical velocity in the distribution network as ports 9 areclosed and opened, and provides a purging clean air stream CAS to clearagricultural products 19 from delivery conduits 11 and manifolds 23downstream of a closed port valve 21. The present apparatus 1 is simpleand less costly to make compared to the prior art system where a two wayvalve with appropriate controls is required to simultaneously open thepurging air conduit while closing the port valve. In the presentapparatus 1 only a simple on/off port valve 21, with appropriate simplecontrols is required. The purging air flow is constantly present and theflow rate thereof increases to purge the delivery conduits 11 when thecorresponding port valves 21 close, and drops to a negligible amountwhen the port valves 21 open.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous changes and modifications willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly, all such suitable changes or modificationsin structure or operation which may be resorted to are intended to fallwithin the scope of the claimed invention.

What is claimed is:
 1. An air distribution apparatus for an air seeder,the apparatus comprising: a manifold body, and a plurality of portsdefined through a wall of the manifold body; a delivery conduitconnected at an input end thereof to each port; a supply conduitconnected at an output end thereof to an interior of the manifold body,and connected at an input end thereof to receive a product air streamwith agricultural products entrained therein; on at least a first port,a port valve configured such that when the port valve is open, acorresponding first delivery conduit is connected to an interior of themanifold body through the first port and a first portion of the productair stream flows through the first delivery conduit, and such that whenthe port valve is closed, the first delivery conduit is disconnectedfrom the interior of the manifold body; a purging conduit connected atan input end thereof to the supply conduit at a clean air locationconfigured to receive from the supply conduit a clean air stream withsubstantially no agricultural products entrained therein, and connectedat an output end thereof to the first delivery conduit in proximity tothe first port such that the clean air stream has an always open pathfrom the supply conduit to the first delivery conduit; and wherein whilethe port valve is open the clean air stream flows through the purgingconduit at a first flow rate, and while the port valve is closed theclean air stream flows through the purging conduit at a second flow ratethat is greater than the first flow rate.
 2. The apparatus of claim 1wherein the supply conduit extends substantially vertically up from themanifold body to a curved elbow and then extends substantiallyhorizontally from the elbow, and wherein the clean air location is at aninner radius of the elbow.
 3. The apparatus of claim 1 wherein the firstdelivery conduit is connected at an output end thereof to a secondarymanifold.
 4. The apparatus of claim 1 wherein the first delivery conduitis connected at an output end thereof to a furrow opener.